Question

which experiment summary best illustrates how yellow fever is spread?
a in building 1, volunteers became sick when they wore filthy, yellow fever - contaminated clothing for three weeks.
b in building 2, a volunteer became sick when he was bitten by mosquitoes infected with yellow fever.
c in building 2, volunteers became sick when they breathed the air that was infected with yellow fever.
d in building 2, volunteers became sick when they came into contact with patients infected by yellow fever.

Explanation:

Yellow fever is a viral disease that is transmitted by mosquitoes. Option B shows a volunteer getting sick after being bitten by mosquitoes infected with yellow fever, which aligns with the known mode of transmission (mosquito - borne). Option A (contaminated clothing) is not the typical mode of transmission. Option C (air - borne) is incorrect as it is not the way yellow fever spreads. Option D (contact with patients) is also not the main mode of transmission for yellow fever.

Answer:

B. In Building 2, a volunteer became sick when he was bitten by mosquitoes infected with yellow fever.